Rapidly Responsive and Highly Selective Fluorescent Probe for Bisulfite Detection in Food

The new fluorescent probe 4-hydroxy-3-((2E,4E)-5-phenylpenta-2,4-dienoyl)-2H-chromen-2-one (probe 1) was designed and synthesized for selective detection of sulfite. The fluorescence intensity of the probe was decreased only in the presence of HSO₃^-; all other anions assessed resulted in an increased fluorescence response. Hence, probe 1 acts as a highly selective sensor for HSO₃^-. This sulfite sensitivity can also be readily monitored visually, as once treated with sulfite the solution shows a marked color change from yellow to colorless. Moreover, probe 1 can be conveniently used as a signal tool to determine the HSO₃^- levels in various sugar samples.